A fuse is a protection device which trips dependent on a current level of a current and dependent on a time duration during which the current level prevails. A fuse, for example, trips virtually instantaneously if the current is higher than a maximum current, does not trip if the current is a rated current or below, and trips after a delay time that is dependent on the current level if the current is between the rated current and the maximum current. A fuse may be used to protect a load and a cable between a power source and the load. The function of a fuse can be implemented using an electronic switch and a drive circuit.
In a complex system a plurality of electric loads and, therefore, a plurality of fuses may be required. In a car, for example, rated currents of loads implemented in the car may range from several milliamps to several 10 amps. Usually cables between a power source such as the car battery and these loads are chosen based on the rated currents of the individual loads. Consequently, different types of fuses are required in order to protect the different types of cables. This, however complicates the manufacturing and supply process.
There is therefore a need for an electronic circuit that functions as a fuse and can be used for different types of loads and cables.